This sketchup plugin can be applied to create fake ambient occlusion in SketchUp with various colors for concave and convex edges which are adjusted in the material editor. By default, the concave material is dark to create the edge look like a shadow and the convex edges are painted white to provide a highlight effect.

Once the tool is operated all the convex edges are concealed but another tool button is arranged to simply switch concealed geometry on and off so as to unhide the convex edges as per your requirement.

Besides, three pages are built with various edge widths in order that your favorite can be selected easily.